// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_AUDIO_NULL_AUDIO_SINK_H_
#define MEDIA_AUDIO_NULL_AUDIO_SINK_H_

#include <memory>
#include <string>

#include "base/macros.h"
#include "media/base/audio_renderer_sink.h"

namespace base {
class SingleThreadTaskRunner;
}

namespace media {
class AudioBus;
class AudioHash;
class FakeAudioWorker;

class MEDIA_EXPORT NullAudioSink
    : NON_EXPORTED_BASE(public SwitchableAudioRendererSink) {
public:
    NullAudioSink(const scoped_refptr<base::SingleThreadTaskRunner>& task_runner);

    // AudioRendererSink implementation.
    void Initialize(const AudioParameters& params,
        RenderCallback* callback) override;
    void Start() override;
    void Stop() override;
    void Pause() override;
    void Play() override;
    bool SetVolume(double volume) override;
    OutputDeviceInfo GetOutputDeviceInfo() override;
    bool CurrentThreadIsRenderingThread() override;
    void SwitchOutputDevice(const std::string& device_id,
        const url::Origin& security_origin,
        const OutputDeviceStatusCB& callback) override;

    // Enables audio frame hashing.  Must be called prior to Initialize().
    void StartAudioHashForTesting();

    // Returns the hash of all audio frames seen since construction.
    std::string GetAudioHashForTesting();

protected:
    ~NullAudioSink() override;

private:
    // Task that periodically calls Render() to consume audio data.
    void CallRender();

    bool initialized_;
    bool started_;
    bool playing_;
    RenderCallback* callback_;

    // Controls whether or not a running hash is computed for audio frames.
    std::unique_ptr<AudioHash> audio_hash_;

    scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
    std::unique_ptr<FakeAudioWorker> fake_worker_;
    std::unique_ptr<AudioBus> audio_bus_;

    DISALLOW_COPY_AND_ASSIGN(NullAudioSink);
};

} // namespace media

#endif // MEDIA_AUDIO_NULL_AUDIO_SINK_H_
